Here you can add contents in call to action if you want to use more features such as Text rotate effect, background images or their location than you have to buy premium version .
In WordPress dashboard go to appearance submenu and click on customize.
After clicking on customize you will in theme customizer.
Here you have to click on Call to Action than Content.
Here you can select or change a page by the selecting a page from a dropdown list and here you can also edit the button label & link .